<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js white furnace test</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<link type="text/css" rel="stylesheet" href="main.css">
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		<div id="container">
			<div id="info">
				<a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> -
				<a href="https://google.github.io/filament/Filament.md.html#toc4.7.2" target="_blank" rel="noopener">White Furnace</a> energy conservation test by <a href="https://jsantell.com/" target="_blank" rel="noopener">Jordan Santell</a>
				<br>Roughness increases left to right
				<br>Metalness increases top to bottom
			</div>
		</div>

		<script type="importmap">
			{
				"imports": {
					"three": "../build/three.module.js",
					"three/addons/": "./jsm/"
				}
			}
		</script>

		<script type="module">

			import * as THREE from 'three';

			let scene, camera, renderer, radianceMap;

			const COLOR = 0xcccccc;

			function init() {

				const width = window.innerWidth;
				const height = window.innerHeight;
				const aspect = width / height;

				// renderer

				renderer = new THREE.WebGLRenderer( { antialias: true } );
				renderer.setSize( width, height );
				renderer.setPixelRatio( window.devicePixelRatio );
				document.body.appendChild( renderer.domElement );

				window.addEventListener( 'resize', onWindowResize );

				document.body.addEventListener( 'mouseover', function () {

					scene.traverse( function ( child ) {

						if ( child.isMesh ) child.material.color.setHex( 0xffffff );

					} );

					render();

				} );

				document.body.addEventListener( 'mouseout', function () {

					scene.traverse( function ( child ) {

						if ( child.isMesh ) child.material.color.setHex( 0xccccff ); // tinted for visibility

					} );

					render();

				} );

				// scene

				scene = new THREE.Scene();

				// camera
				camera = new THREE.PerspectiveCamera( 40, aspect, 1, 30 );
				camera.position.set( 0, 0, 18 );

			}

			function createObjects() {

				const geometry = new THREE.SphereGeometry( 0.4, 32, 16 );

				for ( let x = 0; x <= 10; x ++ ) {

					for ( let y = 0; y <= 10; y ++ ) {

						const material = new THREE.MeshPhysicalMaterial( {
							roughness: x / 10,
							metalness: y / 10,
							color: 0xffffff,
							envMap: radianceMap,
							envMapIntensity: 1,
							transmission: 0,
							ior: 1.5
						} );

						const mesh = new THREE.Mesh( geometry, material );
						mesh.position.x = x - 5;
						mesh.position.y = 5 - y;
						scene.add( mesh );

					}

				}

			}

			function createEnvironment() {

				const envScene = new THREE.Scene();
				envScene.background = new THREE.Color( COLOR );

				const pmremGenerator = new THREE.PMREMGenerator( renderer );
				radianceMap = pmremGenerator.fromScene( envScene ).texture;
				pmremGenerator.dispose();

				scene.background = envScene.background;

			}

			function onWindowResize() {

				const width = window.innerWidth;
				const height = window.innerHeight;

				camera.aspect = width / height;
				camera.updateProjectionMatrix();

				renderer.setSize( width, height );

				render();

			}

			function render() {

				renderer.render( scene, camera );

			}

			Promise.resolve()
				.then( init )
				.then( createEnvironment )
				.then( createObjects )
				.then( render );

		</script>
	</body>
</html>
